Keyboard plate tilt control structure

ABSTRACT

A keyboard plate tilt control structure provided between a keyboard plate and a sliding rail assembly for controlling the tilt angle of the keyboard plate is disclosed to include a crank pivoted to the sliding rail assembly for rotation by the user to adjust the tilt angle of the keyboard plate, a coupling frame fixedly mounted on the bottom side of the keyboard plate and coupled to the crank through a slip joint, a crank lock for locking the crank, and a keyboard plate lock for locking the keyboard plate in horizontal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the keyboard plate structureof a computer desk and more particularly, to a keyboard plate tiltcontrol structure that allows the user to adjust the tilt angle of thekeyboard for data entry operation comfortably.

2. Description of the Related Art

A computer desk has a keyboard rack for carrying a keyboard. Thekeyboard rack comprises a sliding rail assembly, and a keyboard platemounted on the sliding rail assembly. The keyboard plate can be movedwith the sliding rail assembly in and out of the computer desk. Thekeyboard plate is affixed to the sliding rail assembly in horizontal.Therefore, the user cannot tilt the keyboard plate to support thekeyboard in a tilt angle. The user can pull the pivoted foot members ofthe keyboard to the extended position to support the keyboard on thekeyboard plate in a tilt angle. However, this tilt angle does not fitevery user. It is uncomfortable to operate a keyboard that is held inhorizontal or in a small tilt angle.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances inview. It is the main object of the present invention to provide akeyboard plate tilt control structure, which enables the user to adjustthe keyboard plate to one of a series of tilt angles to support akeyboard in the desired angular position for data entry operationcomfortably.

To achieve this and other object of the present invention, the keyboardplate tilt control structure is provided between the bottom side of akeyboard plate and the top side of a sliding rail assembly forcontrolling the tilt angle of the keyboard plate relative to the slidingrail assembly, comprising: a crank transversely coupled to the slidingrail assembly and movable in transverse direction relative to thesliding rail assembly within a distance and rotatable relative to thesliding rail assembly, the crank having a first crank element disposedin contact with the bottom side of the keyboard plate and adapted totilt the keyboard plate upon rotation of the crank by the user; acoupling frame fixedly mounted in the bottom side of the keyboard plate,the coupling frame comprising a sliding slot coupled to the first crankelement of the crank; and a crank lock adapted to stop the crank fromrotary motion, the crank lock comprising an index plate fixedly fastenedto the sliding rail assembly, the index plate having a plurality oflocating holes spaced around the crank, and a finger fixedly provided atthe first crank element for selectively engaging one of the locatingholes of the index plate to stop the crank from rotary motion relativeto the sliding rail assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of the preferred embodiment of the presentinvention.

FIG. 2 is an assembly view in an enlarged scale of the preferredembodiment of the present invention.

FIG. 3A is a plain view of a part of the present invention, showing thecrank locked.

FIG. 3B is similar to FIG. 3A but showing the crank unlocked.

FIG. 4A is a schematic side view of the preferred embodiment of thepresent invention, showing the keyboard plate supported in a tiltposition.

FIG. 4B is similar to FIG. 4A but showing the tilt angle of the keyboardplate adjusted.

FIG. 4C is similar to FIG. 4B but showing the tilt angle of the keyboardplate adjusted.

FIG. 4D is similar to FIG. 4C but showing the tilt angle of the keyboardplate zeroed and the keyboard plate lock locked.

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, a keyboard plate tilt control structure isprovided between a sliding rail assembly 10 and a keyboard plate 100 forcontrolling the tilt angle of the keyboard plate 100, comprising a crank20, a coupling frame 30, a crank lock 40, a keyboard plate tilter 50,and a keyboard plate lock 60.

The crank 20 is pivoted to the sliding rail assembly 10, having a firstcrank element 21 suspending above the sliding rail assembly 10, a secondcrank element 22 connected to one end of the first crank element 21 andextended out of one lateral side of the sliding rail assembly 10, and agrip 23 connected to one end of the second crank element 21 remote fromthe first crank element 21. The design of the second crank element 22enables the moving direction and angle of the first crank element 21 tobe in conformity with the grip 23 when the user operates the grip 23 torotate the crank 20.

The coupling frame 30 is fixedly fastened to the bottom side of thekeyboard plate 100, having two parallel sliding slots 31 that extend indirection toward the front side 101 of the keyboard plate 100 and arecoupled to the first crank element 21 of the crank 20.

The crank lock 40 comprises an index plate 41 fixedly fastened to thesliding rail assembly 10 at one lateral side in a vertical position andhaving a plurality of locating holes 43 formed in the index plate 41 andspaced around the pivot point between the crank 20 and the sliding railassembly 10, and a finger 42 fixedly connected to the first crankelement 21 of the crank 20 and aimed at the index plate 41. Actually,the crank 20 is pivoted to the index plate 41.

The keyboard plate tilter 50 comprises an axle 51 transversely providedat the front side of the sliding rail assembly 10, two lugs 53 fixedlyfastened to the bottom side of the keyboard plate 100 and respectivelypivoted to the two distal ends of the transverse axle 51, and torsionalsprings 52 adapted to support the keyboard plate 100 on the sliding railassembly 10 in a tilt position. The torsional springs 52 are mounted onthe transverse axle 51, each having one end 521 stopped at the top sideof the sliding rail assembly 10 and the other end 522 stopped againstthe bottom side of the keyboard plate 100.

The keyboard plate lock 60 comprises a female locking member, forexample, a retaining hole 61 formed in the top side of the sliding railassembly and spaced from the axle 51 at a distance, and a male lockingmember, for example, a retaining bolt 62 fixedly provided at the bottomside of the keyboard plate 100 and spaced from the coupling frame 30 atone side opposite to the lugs 53.

Referring to FIG. 1 again, the index plate 41 has a pivot hole 411 inaxial alignment with a barrel 412 at the sliding rail assembly 10. Theindex plate 41 and the barrel 412 are bilaterally disposed at the topside of the sliding rail assembly 10 and aligned in a line. The firstcrank element 21 has a first end pivotally coupled to the barrel 412 anda second end pivotally coupled to the pivot hole 411. The second crankelement 22 has one end fixedly axially connected to the second end ofthe first crank element 21 and the other end fixedly mounted with thegrip 23.

Referring to FIGS. 3A and 3B, the crank 20 can be moved in transversedirection across the sliding rail assembly 10 relative to the barrel 412and the index plate 41 within a distance L between a first position,namely, the locking position where the finger 42 is engaged into onelocating hole 43 of the index plate 41 to stop the crank 20 fromrotation relative to the index plate 41 (see FIG. 3A), and a secondposition, namely, the unlocking position where the finger 42 isdisengaged from the locating holes 43 of the index plate 41 and thecrank 20 can be rotated relative to the index plate 41.

Referring to FIG. 4A and FIG. 2 again, the first crank element 21 iscoupled to the sliding slots 31 of the coupling frame 30, and thetorsional springs 52 impart an upward pressure to the keyboard plate 100relative to the sliding rail assembly 10, and therefore, the keyboardplate tilter 50 steadily supports the keyboard plate 100 on the slidingrail assembly 10 in a tilt angle.

Referring to FIGS. 4A-4C and FIGS. 3A and 3B again, the user can movethe crank 20 in transverse direction across the sliding rail assembly 10from the locking position to the unlocking position to disengage thefinger 42 from the locating holes 43 of the index plate 41 and then turnthe crank 20 to shift the finger 42 from one locating hole 43 to anotherto adjust the tilt angle of the keyboard plate 100 relative to thesliding rail assembly 10. When adjusted, the crank 20 is pulledbackwards to engage the finger 42 into the corresponding locating hole43. According to the present preferred embodiment, the index plate 41has three locating holes 43 spaced around the pivot hole 411 atdifferent angles.

Referring to FIG. 5 and FIG. 4D, the user can move the crank 20 intransverse direction across the sliding rail assembly 10 from thelocking position to the unlocking position to disengage the finger 42from the locating holes 43 of the index plate 41 and then turn the crank20 to the position where the first crank element 21 is maintained inparallel to the sliding rail assembly 10. At this time, the user canpress the keyboard plate 100 to force the retaining bolt 62 intoengagement with the retaining hole 61, and therefore the keyboard plate100 is locked to the sliding rail assembly 10 in a horizontal positionso that the user can push the keyboard plate 100 and the sliding railassembly 10 back to the inside of the computer desk (not shown).

A prototype of keyboard plate tilt control structure has beenconstructed with the features of FIGS. 1-5. The keyboard plate tiltcontrol structure functions smoothly to provide all of the featuresdiscussed earlier.

Although a particular embodiment of the invention has been described indetail for purposes of illustration, various modifications andenhancements may be made without departing from the spirit and scope ofthe invention. Accordingly, the invention is not to be limited except asby the appended claims.

1. A keyboard plate tilt control structure provided between the bottomside of a keyboard plate and the top side of a sliding rail assembly forcontrolling the tilt angle of said keyboard plate relative to saidsliding rail assembly, the keyboard plate tilt control structurecomprising: a crank transversely coupled to said sliding rail assemblyand movable in transverse direction relative to said sliding railassembly within a distance and rotatable relative to said sliding railassembly, said crank having a first crank element disposed in contactwith the bottom side of said keyboard plate and adapted to tilt saidkeyboard plate upon rotation of said crank by the user; a coupling framefixedly mounted in the bottom side of said keyboard plate, said couplingframe comprising a sliding slot coupled to said first crank element ofsaid crank; and a crank lock adapted to stop said crank from rotarymotion, said crank lock comprising an index plate fixedly fastened tosaid sliding rail assembly, said index plate having a plurality oflocating holes spaced around said crank, and a finger fixedly providedat said first crank element for selectively engaging one of the locatingholes of said index plate to stop said crank from rotary motion relativeto said sliding rail assembly.
 2. The keyboard plate tilt controlstructure as claimed in claim 1, further comprising spring meansconnected between said keyboard plate and said sliding rail assembly tosupport said keyboard plate on said sliding rail assembly in a tiltangle.
 3. The keyboard plate tilt control structure as claimed in claim2, wherein said spring means comprises a plurality of metal springmembers.
 4. The keyboard plate tilt control structure as claimed inclaim 3, wherein said metal spring members are torsional springs.
 5. Thekeyboard plate tilt control structure as claimed in claim 4, whereinsaid torsional springs are mounted on a transverse axle at a front sideof said sliding rail assembly, each having a first end stopped againstsaid sliding rail assembly and a second end stopped against the bottomside of said keyboard plate.
 6. The keyboard plate tilt controlstructure as claimed in claim 2, further comprising a keyboard platelock adapted to lock said keyboard plate in a horizontal position inparallel to said sliding rail assembly.
 7. The keyboard plate tiltcontrol structure as claimed in claim 6, wherein said keyboard platelock comprises a retaining hole formed in said sliding rail assembly,and a retaining bolt fixedly provided at the bottom side of saidkeyboard plate for engaging said retaining hole when said keyboard plateis turned to horizontal.
 8. The keyboard plate tilt control structure asclaimed in claim 1, wherein said crank has a grip at one end thereof. 9.The keyboard plate tilt control structure as claimed in claim 8, whereinsaid crank further comprises a second crank element connected betweensaid first crank element and said grip.
 10. The keyboard plate tiltcontrol structure as claimed in claim 9, wherein said first crankelement and said second crank element curve in same direction.